A traditional inkjet recording device includes a recording head including a plurality of recording elements for discharging ink, and moves the recording head relative to a recording medium while the recording elements discharge ink onto the recording medium and thereby records an image on the recording medium. Various types of ink to be discharged have been developed. Examples of such ink include a phase change ink involving phase transition from a solid to a liquid and rapidly solidifying after adhering on the recording medium to be fixed thereon.
To respond to requests, such as higher recording rates, a recent inkjet recording device uses a technique of forming long head units (recording means) having a plurality of recording heads disposed at different positions along the width direction orthogonal to the direction of the movement relative to the recording medium. The recording heads of the long head units are each provided with recording elements from which ink is discharged for recording of an image. One known type of such long head units has recording heads disposed in a staggered manner such that the recording heads overlap with each other at their ends along the width direction.
An inkjet recording device including such long head units uses a known technique of causing two recording heads to complementary perform an operation regarding discharge or non-discharge of ink from the recording elements in the recording heads, that is, the output operation in the overlapping range overlapping the two recording heads in the width direction. The occurrence of discontinuity in density at the seams of the recording heads are thereby reduced. For example, Patent Literature 1 discloses a technique of gradually decreasing or increasing the operation rate which is the rate of the output operation of the recording elements in the recording heads within the overlapping range of the two recording heads in the width direction in a complementary manner and thereby reducing the unevenness in ink density.